This is a double-blind, randomized, Phase II study administering the nucleoside analogues ZDV and/or ddl alone, in sequence, or in combination, and a placebo arm for comparison. There will be a two week pre-treatment observation period in which a baseline will be established using virologic measurements. Subjects will then be randomized to one of six treatment arms in a blinded fashion. Study treatment will be given for 32 weeks, followed by a four week post-treatment evaluation period.